Field of the Invention
The present invention relates to a display device, and more particularly to an image processing method and an image processing circuit that are capable of reducing deterioration and color distortion of a fixed image region and extending a lifespan of the image processing circuit, and an organic light emitting diode display device using the same.
Discussion of the Related Art
Representative examples of flat panel display devices include a liquid crystal display (LCD) device, an organic light emitting diode (OLED) display device using OLEDs, an electrophoretic display (EPD) device using electrophoretic particles. Among these flat panel display devices, the OLED display device uses an OLED element, which is configured such that an organic light emission layer between an anode and a cathode emits light itself on the basis of individual sub-pixels. Consequently, the OLED display device exhibits excellent image quality, including a high contrast ratio, and therefore has been spotlighted as a next-generation display device in various field ranging from small-sized mobile devices to large-sized TVs.
In the OLED display device, however, the OLED elements deteriorate over time due to self-emission of the OLED elements. As a result, the luminance of the OLED elements is lowered. Particularly, in a fixed image region where a fixed non-moving image is displayed for a long time (e.g., a menu or icon of a mobile device), the OLED elements emit light based on high gray scale data for a long time. As a result, the OLED elements are rapidly deteriorated, and luminance is lowered, whereby a screen burn-in problem occurs.
In order to solve this problem, a technology has been adopted in an OLED display device to correct luminance for data of the fixed image region on a per pixel basis. The luminance correction method of the related art improves image quality for a short period. However, luminous efficacies of sub-pixels having different colors are not taken into account. As a result, OLED elements of a color having lower luminous efficacy deteriorate relatively rapidly. This causes color distortion. In addition, in the luminance correction method of the related art, deterioration of the OLED elements is accelerated by luminance correction, which shortens the lifespan of the display device.